Draw the fixed features first

Sketch the boundary, buildings, walls, fences, mature trees, slopes, drains, paths, gates and water points. Add dimensions where they affect bed placement or access. Mark doors, inspection covers, utility routes and areas that must remain clear. A rough measured plan is more useful than a polished drawing that omits practical constraints.

Note which features may change. A deciduous tree casts different shade across the year, a hedge grows wider, and a neighbouring structure may redirect wind or runoff. Photograph the site from fixed positions so later observations can be compared. Keep a garden site-assessment record for each proposed growing zone using these fields: zone; date and conditions; observation; next step. Make separate entries for sunlight, soil, drainage, wind, frost and access. Mark unobserved conditions as unknown and record what to check on a later visit so assumptions remain distinct from evidence.

Map direct sunlight over time

Label each possible growing area on your plan so observations can be compared by zone. On several clear days, record the date and the start and end of each observed direct-sun interval in each zone. Mark periods you did not observe as unknown. Record the season, because sun angle and day length change substantially, and revisit the same zones in another season. A site described as sunny in spring may be shaded by trees in summer, while a winter assessment can underestimate the light available during the main growing season.

Separate direct sun from general brightness. Fruiting crops usually need the strongest positions, while many leafy crops can use areas with shorter direct-light periods. Walls and fences can create narrow bands of shade, so divide the garden into useful light zones rather than assigning one label to the whole plot.

Inspect soil and previous use

Check whether the surface is existing soil, imported fill, compacted subsoil or material left from construction. Observe colour, visible organic matter, stones, rooting depth and how difficult it is to insert a fork or trowel when the soil is moist but not saturated. Dig small inspection holes in representative areas where it is safe to do so.

Investigate the site's history before growing food. Land near older painted structures, former industry, heavily trafficked roads, treated timber, ash deposits or unknown fill may warrant professional soil testing for contaminants. Do not rely on appearance alone. Confirm underground services before substantial digging and follow local guidance where contamination is suspected.

Watch water after rain

Visit during or soon after sustained rain. Mark puddles, runoff routes, eroded areas and places that remain wet long after the rest of the garden drains. Also identify dry zones beneath eaves, dense trees or overhanging structures. One simple test hole cannot represent an entire site, particularly where the soil profile has been disturbed.

Find where roof and hard-surface water goes and ensure a new bed will not block a drain or divert water toward a building or neighbour. If flooding, persistent waterlogging or structural drainage is involved, seek appropriate local or professional advice before installing a bed.

Record wind, shelter and temperature pockets

Observe prevailing wind as well as gusts channelled between buildings. Wind increases water loss, damages large leaves and can make supports unreliable. Existing shelter may help, but solid barriers can create turbulence immediately behind them. Note where a permeable windbreak or lower crop might reduce exposure without casting excessive shade.

Look for warm walls, cold hollows and places where frost lingers. A south-facing wall in the Northern Hemisphere, or north-facing wall in the Southern Hemisphere, may create a warmer local climate, while the bottom of a slope may collect cold air. Treat these as observations to test across a season, not permanent guarantees.

Test access and routine work

Walk the route from storage and water supply to every proposed bed. Use a brief layout checklist: record gate openings, narrow points, turning space, comfortable bed reach, and the route from water and storage. Check these against the loaded wheelbarrow, hose, mobility aid or tools you actually use, recording where passage or turning is awkward. Test comfortable reach from the proposed path before fixing bed edges. Keep beds narrow enough to reach without stepping on growing soil and paths usable after rain. A productive corner is a poor choice if watering and harvesting it are consistently awkward.

Consider children, pets, shared access, visibility and security. Avoid placing edible crops where runoff, repeated animal fouling, vehicle fluids or spray from neighbouring activities creates an unmanaged risk.

Turn observations into growing zones

Compare the recorded conditions for each zone, noting the dates and seasons observed. Identify unresolved constraints and mark unobserved conditions as unknown. Label zones by their observed limiting conditions: strongest light, partial shade, wet, dry, exposed, sheltered or difficult to access. Match crops and methods to those zones using the plant guides. Use the most dependable area for the first bed and leave uncertain areas available for observation or a low-cost trial. Record what needs further observation and when to revisit it, allowing for seasonal changes. Then use “Turn the survey into a bed plan” to develop the layout.

Observe before building

If possible, record one wet period, one dry period and the main-season sunlight before making permanent changes. A small trial bed can test assumptions while preserving flexibility.